Hitherto, there have been proposed a charging apparatus able to charge a rechargeable battery in a battery pack inserted into a mobile phone or other information processing device by using a standardized wireless power format.
At this point, exemplary operation of a conventional charging apparatus will be described with reference to FIG. 17.
FIG. 17 illustrates how a conventional charge pad 102 charges a mobile device 101.
A flat charge pad 102 used as a charging apparatus is provided with a thin, plate-shaped receptacle 103 and is able to receive power from a power supply apparatus not illustrated and wirelessly charge a rechargeable battery provided in a mobile device 101 placed on the receptacle 103. Herein, “wirelessly” refers to the mobile device 101 and the charge pad 102 being able to exchange power, signals, etc. while in a state of not being directly electrically connected via coils respectively provided therein.
In the charge pad 102, a transmitter coil 104 is provided inside the receptacle 103. When a coil for position detection disposed with the receptacle 103 overlaid detects the position where the mobile device 101 was placed, the transmitter coil 104 approaches the mobile device 101 placed on the receptacle 103 and charges a rechargeable battery. The technique of a transmitter coil 104 inside a receptacle 103 moving to charge a mobile device 101 is called the “moving coil technique”.
Meanwhile, technology related to a charger that wirelessly charges electronic devices is disclosed in PTL 1. With this technology, the intervals between the generation times of a signal that checks if an electronic device has been placed on the charger in a chargeable state and a command that checks if an electronic device has requested a recharge are made to differ, and a recharge is conducted if there is a decrease in the charge level of a rechargeable battery provided in an electronic device which has finished charging.
Also, technology that determines to stop or continue transmitting power to a primary coil according to the value of a detection current is disclosed in PTL 2.